Among the most sophisticated designs at the time of its creation,[2][3][4] incorporating many new features such as detachable jump sails that would go on to become standard, the Aegis boasted excellent firepower and maneuverability.[2] The Aegis went on to serve with the Hegemony Armed Forces until 2531, when a number of refits designed to keep pace with newer vessels failed, the decision was made to retire the aging class in favor of the Avatar-class.[3][4] However, Deborah Cameron, the cautious Director-General of the Terran Hegemony at the time, chose to send the 106[2] surviving ships to mothballs just in case. This was to prove a boon to the newly formed Star League who found a critical need for WarShips to serve in the Reunification War, with First LordIan Cameron ordering the return of the Aegis cruisers to active duty in 2582. One-third of the cruisers - 30[3][4] to 36[2] vessels in all - were turned over to the Council Lords to be added to their private fleets, with the rest entering Hegemony shipyards to be refitted for use in the Star League Navy.[2][3][4] The Great Houses would continue to operate at least some of the donated Aegis cruisers throughout the Star League era, despite the reduction in size of their active fleets during the general disarmament of the period; as late as 2765 the Capellan Confederation was operating six Aegis cruisers as a part of its black water navy, making the Aegis the second most common WarShip in the thirty-seven strong fleet,[5] while the Draconis Combine was operating five,[6] the Federated Suns six,[7] the Free Worlds League at least five[8] and the Lyran Commonwealth three during the same period.[9]

Di Tron spent the next ten years[3][4] transforming the relics into some of the most advanced warships of their time. The newer equipment was mostly smaller than the old, and there was enough room to add a few amenities, such as a Zero-G pool.[2] One of the most important innovations was the Lithium-Fusion Battery System,[2][3][4] the Aegis being among the first designs to receive it across the class. The archaic and age worn materials and construction techniques made the hull of the Aegis weaker than on later ships, also leaving the ship more easily detected by enemy sensors,[2] but a surprising number survived the fall of the Star League and departed the Inner Sphere during the Exodus. A number of these craft have been observed in Clan toumans, the design highly favored by Clan Jade Falcon who use it to perform escort and transport duties.[3][4]

The original Aegis class had bunk space for a crew of 768,[4] whereas the upgraded vessels required only somewhat more than 180 crew members.[3][4] The spare capacities make the Aegis notably well-suited for rescue and evacuation operations.[10]

The main firepower of the Aegis is its eighteen Armstrong II 35-Series naval autocannons, two each in the nose and each forward angle with four on each broadside and mounted aft, and eight White Shark missile tubes, three on each fore angle with two directly aft. The secondary large-caliber armament is intended to defend the fighter launch bays and consists of three Randall-55 NL55s and a single Barracuda tube on each broadside, a further three NL55s, Barracuda tube and six Imperator-20 NAC/20s on each rear angle, with four Magna-45 NL45s directly aft.[2][3][4]

The Clan version differs little from those used by the SLDF and ComStar, save a minor reduction in armor and cargo space to boost the fighter compliment to twenty, 2 Stars, in line with Clan military structure. BV (1.0) = 167,790[4]

A unique, one-of-a-kind ship, the SLS Manassas was modified to carry an experimental jump drive with a pre-booster system that enabled the ship to jump up to 40 light-years per jump, 10 more than the usual 30 light-year upper limit on jump engines.[11]